Conventional riflescopes include objective and eyepiece lens systems positioned at opposite ends of an elongate tubular housing, and an image erecting lens system placed between the objective and eyepiece lens systems. An aiming reticle including crosshairs or another aiming pattern is typically placed either at a first focal plane, between the objective and erector, or at a second focal plane, between the erector and eyepiece.
Several different mechanisms are known for adjusting the aim of a riflescope to compensate for crosswinds (windage) and/or ballistic drop (elevation). These mechanisms include: (1) a scope mount that adjusts the alignment of an entire riflescope relative to the firearm on which the scope is mounted, as described in U.S. Pat. No. 2,143,167 of Pechar; (2) a mechanism for laterally adjusting the position of the reticle within the housing relative to the image formed at one of the image planes of the scope, as described in U.S. Pat. No. 2,913,826 of Petty; (3) a pivoting mount for the erector lens system (usually a “pivot tube”), which enables the erector lens system to be pivotably moved from center to change the lateral position of the image formed at the second focal plane, where a reticle is located, as described in U.S. Pat. No. 3,161,716 of Burris et al., U.S. Pat. No. 3,184,852 of Hageman, U.S. Pat. No. 3,684,376 of Lessard, and U.S. Pat. No. 4,408,842 of Gibson (NB: In some of these systems the pivot tube is pivotably supported near the eyepiece, and in others the pivot tube is pivotably supported near the objective.); and (4) Pivoting of an image erecting prism system onto which a reticle pattern is projected, as described in U.S. Pat. No. 4,806,007 of Bindon.
U.S. Pat. No. 5,771,623 of Pernstich et al. describes a telescopic sight including an objective lens that is also the objective lens of an integrated laser rangefinder receiver. Pernstich et al. describe a movable objective that simultaneously adjusts the point of aim of the telescopic sight and the aim of the laser rangefinder. In one embodiment, shown in FIG. 2 of the '623 patent, the objective is mounted within a pivot mount. In another embodiment, shown in FIG. 2A of the '623 patent, a “partial lens” of the objective is mounted in a cage that is deflected laterally by a pair of adjusting screws. The cage is connected to the scope housing by a set of spring pins. Due to the arrangement of the spring pins, any lateral adjustment of the partial lens would also necessarily impart some tilting or pivoting of the partial lens and some displacement of the partial lens longitudinally along the optical axis of the telescopic sight, similarly to the embodiment of FIG. 2 of the '623 patent.
The present inventor has identified a need for an improved aiming mechanism for a riflescope.